Mittens aren't only what pike anglers use to keep their fingers warm in the winter if you fish in the Fens these days, as PAC member Andy Webster discovered when he fished a drain in Lincolnshire.
For when something munched on his deadbait, it wasn't a pike but a Chinese mitten crab.
"I reeled in the float fished sprat and felt a bit of weight on the end but it fell off," Andy said on his blog tonight.
"The sprat had been shredded and I didn't have a clue what could have caused it. I decided to put it back in the same spot and after ten minutes I carefully reeled in again. The crab was wrapped in the trebles."Mittens first hit the headlines when they turned up in the tidal Thames two decades ago. Oringinally believed to have travelled to London's docks in the ballast of cargo ships from the Far East, scientists believe frequent drought years and increased abstraction reduced river flows and created ideal conditions for the interlopers to breed.
Since then, they have spread around our shores, taking upwards of 20 years to walk around
our coastline to The Wash, from where they are believed to have entered the Tidal Ouse.
One turned up in a fish trap at Denver two years back and anglers were urged to report captures to the Environment Agency.
Another specimen ws caught recently on the Yorkshire Ouse - click here for local paper report.
As well as having a nasty nip mittens - so called because their claws grow fur during the breeding season - have another habit which doesn't go down well in low-lying, climate-change threatened areas like the Fens.
They burrow into the mud, digging large holes which can cause river banks to erode.
Environmentalists are now investigating whether the crabs could be commercially harvested for food as a way of controlling their numbers. But there are concerns over the level of toxins present in their flesh.